Nabtesco Corporation

Kajima Corporation

Shuichi Kamagata

Koji Nakamura

Takuji Kobori

Shunichi Yamada

Masaki Harada

Kazuhiko Sakurai

Koki Akai

Hiroo Kanayama

Mitsuo Sakamoto

Takashi Naruse

Shunsuke Kimura

Yokon Oh

A sensor relating to one embodiment of the present invention includes a first electrode, a second electrode, an attracting portion arranged between the first electrode and the second electrode, where the attracting portion attracts conductive particles smaller than a gap between the first electrode and the second electrode to cause a change in electrical resistance between the first electrode and the second electrode, and a short circuit preventing portion for preventing a large-diameter conductive piece from causing a short circuit between the first electrode and the second electrode, where the large-diameter conductive piece has a larger dimension than the gap between the first electrode and the second electrode.

Sensor

A speed reducer includes an outer tubular member, internal tooth pins, oscillating gears and a carrier block. The outer tubular member has pin grooves on an inner circumferential surface thereof. The internal tooth pins are rotatably placed in the pin grooves. The oscillating gears have external teeth smaller in number than the pin grooves, and the oscillating gears are oscillatorily rotatable with the external teeth engaging with the internal tooth pins. The carrier block is cooperatively connected to the oscillating gears such that the oscillating gears are allowed to oscillatorily rotate relative to the carrier block and restricted from rotating on own axis relative to the carrier block. A displacement restricting member configured to restrict the internal tooth pins from being displaced inwardly in a radial direction of the outer tubular member is disposed between the outer peripheries of the oscillating gears adjacent to each other.

Speed reducer

An internal-pressure rise prevention structure of a speed reducer according to the invention includes a speed reduction mechanism that decelerates rotation of an input part and transmits the decelerated rotation to an output part, and a container having a communication hole formed in a wall surface that defines an internal space for accommodating the speed reduction mechanism and lubricant. The communication hole is situated vertically above the level of the lubricant.

Internal-pressure rise prevention structure of speed reducer

The present invention contemplates a rigidity control system for a variable rigidity structure incorporating variable rigidity elements, such as braces, for making the connecting condition with the frame variable between the locked and unlocked conditions for example, in which the vibration of a structure caused by external vibrational forces of an earthquake, wind or the like is attenuated by varying the rigidity of the structure. The rigidity control of the present invention imitates the tension and relaxation of a muscle in the self-balancing function of a living body. The vibrational condition of a frame is considered to be separately four conditions, i.e., the process of increasing the deformation in one direction, the process of decreasing the deformaton following thereafter, the process of increasing the deformation in the opposite direction and the process of decreasing the deformation following thereafter. Continuous responses are detected by sensors and the structure is set to be in the rigid condition in the deformation increasing process to restrain the excessive deformation of the building frame while the structure is set to be in the resilient condition in the deformation decreasing process to continuously vary the rigidity of the frame, whereby the resonance of the frame with seismic motion or the like is avoided to attenuate the vibration.

Rigidity control system for variable rigidity structure

A rigidity control device is provided to change the natural resonance of an entire building by varying the rigidity of selected structural members such as pillars, beams, braces or floor and pillar, wall and pillar or beam connection members, joints, and the like. The rigidity of a structural member is controlled by restraining or releasing a member from restraint or by applying a controlled force to the member. These processes are selectively combined so that the rigidity of the whole building and each section thereof is controlled by a computer according to earthquake forecast analysis. Thus, the proper rigidity of a building is determined and provided responsive to earthquake detection to prevent the building from destructive resonance caused by earthquake tremors.

Device and method for protecting a building against earthquake tremors

A rigidity control device is provided to change the natural resonance of an entire building by varying the rigidity of selected structural members such as pillars, beams, braces or floor and pillar, wall and pillar or beam connection members, joints and the like. The rigidity of a structural member is controlled by restraining or releasing a member from restraint or by applying a controlled force to the member. These processes are selectively combined so that the rigidity of the whole building and each section thereof is controlled by a computer according to earthquake forecast analysis. Thus, the proper rigidity of a building is determined and provided responsive to earthquake detection to prevent the building from destructive resonance caused by earthquake tremors.

A method of controlling a building against an earthquake according to the present invention comprises the steps of analyzing instantly the earthquake on the basis of data observed by earthquake sensors disposed in the building and narrow and wide regions, varying the connecting conditions in the building on the basis of obtained earthquake response forecast to vary the rigidity of the building or giving counter force to a building with an exciter to control oscillation according to individual earthquake characteristics.

Growing community of inventors

Tokyo, Japan

Shuichi Kamagata